The estate of late Oakland Raiders owner Al Davis has been sacked for a loss in a longrunning legal battle with the IRS.

In a ruling Monday, the 9th U.S. Circuit Court of Appeals found that Davis was obligated to pay the government about $2.5 million in a feud with the IRS over three years of federal taxes dating back to 1990. The appeals court overturned a San Francisco federal judge who previously ruled the IRS should refund the tax money to Davis because it had been improperly assessed.

While the 9th Circuit agreed that the IRS made mistakes in dealing with Davis’ tax situation, the court determined the legendary Raiders owner was nevertheless not entitled to the refund under the procedures in his tax court appeals. The judges did note that Davis’ estate may have other options to pursue the money, but took no position on that possibility.

Davis sued the IRS in 2011, just months before his death, leaving his wife Carol and his estate to pursue the legal claims. The dispute centered on three years of federal tax claims, 1990, 1992 and 1995, with the bulk of the refund conflict involving $1.8 million in 1992, according to court papers.

The 9th Circuit described Davis as a “gridiron icon” in the ruling, but also noted that he and the Raiders “were hardly strangers to the courts” by the time he sued the IRS, citing his many legal feuds with the National Football League.

The estate’s lawyer could not immediately be reached for comment.

Howard Mintz covers legal affairs. Contact him at 408-286-0236 or follow him at Twitter.com/hmintz